Something that was always fascinating to me: there had been a time, around 1100, when the style of ceilings in sacral architecture was "discussed" with urgency

Something that was always fascinating to me: there had been a time, around 1100, when the style of ceilings in sacral architecture was "discussed" with urgency and churches went through 3 redesigns and rebuilds in just 10 years (from a flat ceiling, to barrel vault, to cross ribs, which became predominant in about 1105/1107 – there are several examples). This is totally unthinkable nowadays, where buildings that went through planning and construction phases of a decade and more are still considered "dernier ci".